The European Space Agency has decided not to let sleeping spacecraft lie. Early on January 20th, the European Space Agency woke up its Rosetta probe after two-and-a-half years in hibernation. Rosetta launched back in 2004. In 2011 it was put to sleep to wait out some of the long journey to its ultimate destination: Comet 67P/Churyumov-Gerasimenko.

Now it's almost game time, so a pre-programmed alarm clock woke Rosetta. After powering up, the spacecraft pointed its antenna at Earth to signal that it was okay.

[Sound of mission control cheers and announcement: "Ladies and gentlemen, it looks like we have a signal. It looks like Rosetta has indeed woken up."]

Rosetta's relieved parents at the ESA control room.

Rosetta should be close enough to start snapping photos of the comet in May. In August, Rosetta is due to become the first vehicle to rendezvous with a comet. For a couple months, Rosetta will study the icy rock from orbit. Then it will release a probe, which will attempt to make history’s first comet landing.

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